Let's roll up our sleeves and solve this. We have 491 and we're going to multiply it by 4, essentially adding 491 to itself 4 times.
Step 1: 0 + 491 = 491
Step 2: 491 + 491 = 982
Step 3: 982 + 491 = 1473
Step 4: 1473 + 491 = 1964

So, 491*4 = 1964